Magnetic and optical data storage devices, such as hard disk drives (HDDs), tape drives and compact disk drives, use heads to read and write information to and from a storage media. In a typical rotating storage system, data is stored on a disk in a series of adjacent concentric tracks. In a magnetic storage device, the tracks are accessed by read and write heads that move radially over the disk under control of a head-positioning servo mechanism so that the heads can be selectively positioned over a specific track. Once the head is aligned over a track, the servo mechanism causes the heads to ideally follow a center line of the selected track during a read or write operation.
Digital data is written to the storage media in a predetermined format using a write head that induces a magnetic field with sufficient amplitude to record on the magnetic material of the storage device. The magnitude and direction of the magnetic field is modulated to encode information into the magnetic surface of the storage device. The data might then be read as necessary by a read head for processing, for example, by a host computer. In read mode, as the magnetic storage surface moves across the gap in the head, the magnetic field of the storage surface is detected, and a voltage is induced in the head. The analog voltage signal is processed to obtain digital data. For example, the analog voltage might be amplified, filtered, and provided to an analog-to-digital converter (ADC) where the signal is digitized and passed through an equalizer and decoded.
As storage media storage capacities have increased, the data tracks are closer in proximity, increasing storage density and capacity of the media. However, as adjacent data tracks become closer, crosstalk between the adjacent tracks, Inter-Track Interference (ITI), might become increasingly significant, such that data in a desired track cannot be read, leading to data corruption. For example, the read and write heads might be positioned over the storage media by various types of alignment marks that might typically be recorded on the recording disk surface to track and adjust the position of the read and write heads. ITI might be the result of write head positioning error during a write operation, or read head positioning error during a read operation.
In order to detect ITI, typical systems might record tracking marks in one or both adjacent tracks, and read the marks when reading the desired track. However, such ITI cancellation requires seeking to the side tracks and waiting for the media to rotate to the position of the tracking marks. Thus, ITI cancellation could introduce large system latency to read data from the storage media.